Ignition switches



2 Sheets-Sheet 1 Filed Feb. 2, 1967 Dec. 12, 1967 E. CRYER 3,358,093

IGNITION SWITCHES Filed Feb. 2, 1967 2 Sheets-Sheet 2 United StatesPatent 3,358,093 IGNITION SWITCHES Edward Cryer, Burnley, England,assignor to Joseph Lucas (Industries) Limited, Birmingham, England, aBritish company Filed Feb. 2, 1967, Ser. No. 613,656 Claims priority,application Great Britain, Feb. 17, 1966, Ser. No. 7,075/ 66 1 Claim.(Cl. 200-44) 7 ABSTRACT OF THE DISCLOSURE This invention relates toignition switches for road vehicles, comprising as shown in theaccompanying drawing, a casing having a rotor rotatably mounted therein,cam means acting to locate the rotor at any one of a number of positionsrelative to the casing, a contact as sembly arranged to completecircuits in certain positions of the rotor, and an additional switchhaving a fixed part carried by the casing and a movable part carried bythe This invention relates to ignition switches for use in roadvehicles.

A switch according to the invention includes a casing, a rotor, cammeans acting to locate the rotor at any one of a number of positionsrelative to the casing, a contact assembly arranged to complete circuitsin certain positions of the rotor, and an additional switch having afixed part carried by the casing and a movable part coupled to the rotorfor movement therewith.

One example of the invention is illustrated in the accompanying drawingswherein FIGURE 1 is a sectional side view of an ignition switch, FIGURE2 is a sectional view on the line 22 inFIGURE 1, FIGURE 3 is an end viewof the switch viewed in the direction indicated by the arrow A in FIGURE1, and FIGURE 4 is a fragmentary perspective of part of the switch, andFIGURE 5 is a fragmentary sectional view on the line 5-5 in FIGURE 1.

The ignition switch illustrated in the drawings if of the key operatedtype having four operative positions, an off position in which the keymay be removed from the switch, a first position achieved by rotatingthe key in a clockwise direction, in which ignition and auxiliarycircuits of a road vehicle are energised, a second position, achieved byrotating the key further in a clockwise direction, in which a startermotor circuit of the vehicle is also energised, and a third position,achieved by rotating the key in a counterclockwise direction from theoff position, in which only the auxiliary circuit is energised.

Referring to the drawings there is provided a cylindrical casing 11which is stepped to provide a shoulder 18, and is closed at its widerend by an annular contact board 14. A hole in the contact board 14 isclosed by a resilient cup shaped member 51 mounted in a synthetic resinmaterial. The member 51 is formed with a pair of arcuate outwardlyextending flanges 52 at its open end, which engage shoulders 15a formedin the inner face of the board 14 to prevent withdrawal of the member51.

A pair of rivets 53, 54 extending through the base of the member 51 andsecure a pair of terminal blades 55, 56 to the outer face thereof, theheads of the rivets 53, 54 forming contacts 53a, 54a within the member51.

Rotatable within the narrower cylindrical part 12 of the casing 11 isthe core (not shown) of a cylinder lock, the part 12 of the casing 11constituting the barrel of the lock. Within the Wider part 11a of thecasing 11 is a rotor 16, rotatably supported at one end in the member 51and secured at its other end to the core of the lock for rotationtherewith.

The rotor 16 is moulded in a synthetic resin material and is formed witha head 17 of substantially elliptical configuration (FIGURE 2). The head17 abuts against the shoulder 18 of the casing 11 and extending axiallyfrom the head 17 is a hollow substantially cylindrical shank 19, havinga pair of diametrically opposite, longitudinally extending flats (notshown), the end of the shank 19 being rotatably supported in the member51. The shank 19 is also formed with a pair of longitudinally extendingdiametrically opposite slots 22, in which are engaged the ends of anelectrically conductive roller 57. A spring 58 housed within the shank19, urges the roller 57 into contact with cam forms 59, 59a moulded onthe inner wall of the member 51.

Surrounding the shank 19 is an annular contact plate 23 provided withprojections 24, the hole in the plate 23 being shaped complementarily tothe shank 19 so that the plate 23 rotates therewith.

Associated with the board 14 are four contacts 26, 27, 28, 29 each ofwhich incorporates one or more terminal blades positioned externally ofthe plate 14 for connection to external circuits, and a contact portionon the interior of the plate, the contact portions extending into holesin an insulating plate 35 over which the projections 24 move.

The contact plate 23 is urged towards the contact board 14 by a spring36, one free end 36a of which is engaged in a further longitudinal slot22a in the shank 19, and the other free end 36b of which extends towardsthe inner wall of the casing 11.

The rotor 16 is provided with an axially extending bore 38 ofnon-circular cross section with which is engaged a complementarilyshaped spigot which extends from the core of the cylinder lock. Byvirtue of this engagement the rotor 16 is rotatable with the core of thelock. In the head 17 is a radial bore 39 containing a ball 41 which isurged by a spring 42 into engagement with an arcuate cam track 43.

The cam track 43 comprises three angularly spaced depressions 44, 45, 46and a ramp 47. When the switch is in its off position the ball 41 isengaged with the depression 45 of the cam track 43 and the projections24 of the contact plate 23 engage with the insulating member 35. Whenthe switch is in the off position the roller 57 is supported clear ofthe contacts 53a, 54a by the cam forms 59, 59a against which the roller57 is urged by the spring 58.

If it is required to energise the auxiliary circuit of the vehicle anignition key is inserted into the core of the lock and rotated in acounterclockwise direction. Since the core of the lock, the rotor 16,the contact plate 23 and the roller 57 are not rotatable relatively toone another, angular movement of the key results in angular movement ofthe plate 23 relatively to the board 14 and angular movement of theroller 57 relatively to the cam forms 59, 59a of the member 51. Byrotating the key in a counterclockwise direction the plate 23 is movedto a position in which it bridges the input and auxiliary contacts andso completes the auxiliary circuit. The cam forms 59, 59a of the member51 are such that the roller 57 is maintained in a position clear of thecontacts 53a, 54a. When the plate 23 is in the position in which itcompletes the auxiliary circuit the ball 41 engages the depression 44which prevents accidental rotation of the key and consequently the plate23. By virtue of the engagement of the end 36a of the spring 36 with theslot 22 in the shank 19, the spring 36 is rotated with the shank 19.

To complete the ignition circuit of the vehicle the key is turned in aclockwise direction, the ball 41 engages the depression 46 and the plate23 bridges the input, ignition and auxiliary contacts thereby completingthe ignition and auxiliary circuits. The ends 36b of the spring 36 nowengages a lug 37 formed as part of the cam track 43. To energise thestarter motor of the vehicle the key is rotated further in a clockwisedirection which forces the ball 41 to ride up the ramp 47 and causes thecontact plate 23 to bridge the input and starter contacts whilemaintaining the bridge between the input and ignition contacts. However,since the end 36b of the spring 36 is engaged with the lug 37, suchfurther rotation of the key in a clockwise direction causes the springto be twisted, so that if the key is now released the spring 36, nowacting as a torsion spring, will return the switch to its first positionin which the ball 41 engages the depression 46 and the ignition circuitis still completed but the starter motor circuit is broken.

The cam forms 59, 59a include a pair of diametrically oppositedepressions in which the ends of the roller 57 locate when the ignitioncircuit is complete the roller 57 is urged by the spring 58 into thedepressions. These depressions are suificiently deep to ensure that theroller 57 bridges the contacts 53a, 54a so as to complete a circuittherethrough. Thus the switch completes two separate circuits and ineflect acts as a double pole ignition switch.

The part 12 of the casing 11 is externally screw threaded to facilitatemounting of the switch on the dash board or bulkhead of the roadvehicle.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

An ignition switch comprising in combination a first hollow casing, arotor, means mounting the rotor for angular movement within said firstcasing, a contact board closing one end of said first casing, saidcontact board having a central hole formed therein, movable contactscarried by the rotor, co-operating detent means on said first casing andsaid rotor serving to define operative positions of the switch, saidmovable contacts engaging respective fixed contacts carried by saidcontact board in said operative positions, a second casing non-rotatablyengaged in said hole in the contact board, a pair of fixed contactscarried by said second casing, a conductive roller carried by said rotorand located within said second casing, a cam form on the inner surfaceof said second casing, and means urging said roller into engagement withsaid cam form, said roller riding on said cam form as the rotor is movedangularly, and the shape of said cam form being such that said rollerbridges the pair of fixed contacts carried by said second casing in oneof the operative positions of the switch.

References Cited UNITED STATES PATENTS 1,622,707 3/1927 Douglas 200-442,046,831 7/1936 Lowe ZOO-44 X 2,868,906 1/1959 Soreng 200-44 ROBERT K.SCHAEFER, Primary Examiner.

H. HOHAUSER, Antistant Examiner.

